CN102052702A - Heating system and method by using power plant steam turbine bearing cooling water through heat pump - Google Patents

Abstract

The invention belongs to the field of energy and relates to a bearing cooling water heat pump heating system and method in a power plant. The system consists of a steam turbine, a steam turbine bearing cooling system, a steam absorption heat pump, a water-water heat exchanger, a low-pressure heater, a heat network heater and corresponding Composed of piping and ancillary equipment. The system uses the bearing cooling water of the power plant as the low-temperature heat source of the absorption heat pump, and the medium-pressure steam that has done work in the steam turbine unit is used as the driving heat source of the heat pump. It exchanges heat in the absorption heat pump system, and its water is sent to the steam turbine unit for heat recovery system. As the boiler feed water, the heat from the high-temperature heat source obtained by the heat pump system is supplied to the heat user in winter alone or coupled with the traditional cogeneration system, and the condensate of the steam turbine unit is heated in summer by the regenerative heater of the water-to-water heat exchanger Increase boiler feed water temperature. Thus, the bearing temperature of the steam turbine unit in the power plant is reduced, the safe operation of the unit is realized, and the heat is output to the outside through the heat pump for heat supply, which improves the thermal economy of the steam turbine unit.

Description

Power plant steam turbine bearing cooling water heat pump heating system and method

technical field

The invention belongs to the field of energy, and particularly relates to a heating system and method for a steam turbine bearing cooling water heat pump in a power plant. The system reduces the bearing temperature of the steam turbine unit bearing in the power plant through the operation of the steam turbine bearing cooling water heat pump in the power plant and realizes the safe operation of the unit. On the one hand, the obtained heat is output to the outside through the heat pump for heat supply, which realizes the cascade utilization of energy and improves the thermal economy of the steam turbine unit system.

technical background

The bearing cooling of the steam turbine unit in a thermal power plant is one of the problems that affect the safety of the unit operation. When the steam turbine is running at high speed, the internal friction of the bearing will generate a lot of heat. If the bearing temperature is too high, it will cause the unit to vibrate or even shut down. During the operation of the unit, the heat can be taken away by the continuous circulation of the lubricating oil system in the bearing, and then the lubricating oil is cooled by another cooling water system, so as to play a cooling role in the operation of the unit. In actual operation, the cooling water system here needs the external environment to cool down and lower the temperature, and a large amount of heat is wasted into the environment. On the other hand, in summer, due to the high ambient temperature, the cooling effect is poor, and the cooling effect of the bearing is often not good enough to affect the entire steam turbine. group run.

Contents of the invention

The invention provides a heating system and method for a steam turbine unit bearing cooling water heat pump in a power plant.

A steam turbine unit bearing cooling water heat pump heating system in a power plant is characterized in that the system includes a steam turbine, a steam turbine bearing cooling system, a steam absorption heat pump, a water-to-water heat exchanger, a low-pressure heater and a heat network heater; the steam turbine 1 of the system The shaft of the steam turbine is connected to the steam turbine bearing cooling system 3, and the steam turbine bearing cooling system 3 is connected to the evaporator 7-2 of the steam absorption heat pump 7 through a circulating cooling water pipeline; the extraction steam of the steam turbine 1 is connected to the generator 7 of the steam absorption heat pump 7 through a pipeline -1, the drain formed after cooling in the generator 7-1 is connected to the feed water side of the low-pressure heater 6 of the steam turbine recuperation system through the drain pipe; the water supply end of the condenser 7-4 of the steam absorption heat pump 7 is connected to the water supply 3 The one way valve 9 and the water supply three-way valve 9 are connected to the heat network heater 10 supplied to the heat user 11, and the return water end of the condenser 7-4 is connected to the heat network heater supplied to the heat user 11 through the return water three-way valve 8 10 forms a water circulation loop; the water supply three-way valve 9 and the return water three-way valve 8 are respectively connected to the two ends of the water-water heat exchanger 5 of the steam turbine recovery system; the two ends of the water-water heat exchanger 5 of the steam turbine recovery system Both ends of the low-temperature water side are respectively connected to the feed water side of the low-pressure heater 6 and the water outlet end of the regenerative heater corresponding to the corresponding temperature on the side of the condensate pump 4 .

A heating method for a bearing cooling water heat pump of a power plant, characterized in that the heating of the bearing cooling water heat pump of the power plant uses the cooling water of the bearing cooling water of the steam turbine of the power plant as the low-temperature heat source of the absorption heat pump, and uses the low-pressure heat generated by the work done in the power generation steam turbine Steam is used as the driving heat source of the heat pump. The heat obtained by the high-temperature heat source of the heat pump is used for heating in winter, and the feed water heating system connected to the steam turbine is used to heat the boiler feed water in summer.

The beneficial effect of the invention is that on the one hand, the bearing temperature of the steam turbine unit in the power plant is reduced to realize the safe operation of the unit; on the other hand, the heat obtained from the high-temperature heat source of the heat pump system is supplied to the heat user in winter, and the steam turbine unit is heated through a heat exchanger in summer The condensed water increases the boiler feed water temperature.

Description of drawings

Figure 1 is a schematic diagram of the structural form of the heating system of the steam turbine unit bearing cooling water heat pump in the power plant.

In the figure: 1 is the steam turbine, 2 is the condenser, 3 is the cooling system of the steam turbine bearing, 4 is the condensate pump, 5 is the water-water heat exchanger, 6 is the low-pressure heater, 7 is the steam absorption heat pump, 8 is the return water Three-way valve, 9 is a water supply three-way valve, 10 is a heat network heater, 11 is a heat user, 7-1 is a generator, 7-2 is an evaporator, 7-3 is a throttling device, 7-4 is a condensation device.

Detailed ways

The invention provides a heating system and method for a steam turbine unit bearing cooling water heat pump in a power plant.

The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

Example 1

Figure 1 is a schematic diagram of the heating system structure of the steam turbine unit bearing cooling water heat pump, the system includes a steam turbine, condenser, steam turbine bearing cooling system, steam absorption heat pump, condensate pump, water-water heat exchanger, low-pressure heater, supply The return water three-way valve, heating network heater and auxiliary equipment, etc., are composed of corresponding pipeline connections.

The specific working process is as follows: the exhaust steam of steam turbine 1 enters the condenser 2 to condense into water, and then is sent to the boiler as feed water through the heat recovery system composed of condensate pump 4 and low-pressure heater 6; the exhaust steam released by steam turbine 1 during high-speed rotation The heat is cooled by the steam turbine bearing cooling system 3, and the circulating water cooling pipeline is connected to the evaporator 7-2 of the steam absorption heat pump 7 as the low-temperature heat source of the absorption heat pump 7; The generator 7-1 of the heat pump 7, the steam is used as the driving heat source of the absorption heat pump 7, and the steam is cooled after releasing heat, and the drain formed by cooling is connected to the low-pressure heater 6 of the steam turbine recovery system through the drain pipe as part of the boiler feed water Condenser 7-4 is the high-temperature heat source of steam absorption heat pump 7, and it emits heat to the outside world, and the high-temperature water in condenser 7-4 connects water supply three-way valve 9; In winter, by the switch of water supply three-way valve 9, The high-temperature water generated by the steam absorption heat pump 7 is supplied to the heat network heater 10 and further supplied to heat users for heating; in summer, through the switching of the water supply three-way valve 9, the high-temperature water generated by the steam absorption heat pump 7 is exchanged through water and water Heater 5 heats the feed water of the steam turbine recuperation system; the heat network heater 10 and the heater 5 are both water-to-water heat exchangers, and their return water is connected to the return water three-way valve 8, which is connected to the steam absorption heat pump 7 through the three-way valve The condenser 7-4 forms a water circulation loop; the throttling device 7-3 is connected to one end of the condenser 7-4 and the evaporator 7-2, and the generator 7-1 is connected to the condenser 7-4 and the evaporator 7-2 the other end.

Finally, it should also be noted that what is listed above are only specific embodiments of the present invention. Obviously, the present invention is not limited to the above embodiments, and many variations are possible.

The present invention may be embodied in other specific forms without departing from the spirit and main characteristics of the invention. Therefore, the above-mentioned embodiments of the present invention can only be considered as descriptions of the present invention and cannot limit the present invention, and the scope of the present invention is pointed out by the claims, but the above-mentioned explanations do not all point out the scope of the present invention. Therefore, any changes within the meaning and scope equivalent to the claims of the present invention should be considered to be included in the scope of the claims.

Claims (2)

1. the heating system of power plant's bearing cooling water heat pump is characterized in that, this system comprises steam turbine, steam turbine bearing cooling system, steam absorption heat pump, water water-to-water heat exchanger, low-pressure heater and heat exchangers for district heating; The arbor of the steam turbine of this system (1) connects steam turbine bearing cooling system (3), and steam turbine bearing cooling system (3) connects the evaporimeter (7-2) of steam absorption heat pump (7) by the recirculated cooling water pipeline; Drawing gas of steam turbine (1) connects the generator (7-1) of steam absorption heat pump (7), the hydrophobic feedwater side that is connected to the low-pressure heater (6) of Steam Turbine Regenerative System by drain water piping of generator (7-1) by pipeline; The water supply end of the condenser (7-4) of steam absorption heat pump (7) connects Water-supplying tee joint valve (9), a road of Water-supplying tee joint valve (9) connects the heat exchangers for district heating (10) of supplying with hot user (11), and the backwater end of condenser (7-4) connects the heat exchangers for district heating (10) of supplying with hot user (11) by backwater triple valve (8) and forms the loop; By the control of triple valve, in another loop, backwater triple valve (8) and Water-supplying tee joint valve (9) are connected water water-to-water heat exchanger (5) the high temperature heat release side of Steam Turbine Regenerative System respectively; The two ends of water water-to-water heat exchanger (5) the water at low temperature side of Steam Turbine Regenerative System connect the feed-water inlet of low-pressure heater (6) and the bleeder heater water side of condensate pump (4) side corresponding temperature respectively.

2. the heating method of power plant's bearing cooling water heat pump, it is characterized in that, described power plant bearing cooling water heat pump heating is to utilize the low-temperature heat source of power plant steam turbine bearing cooling water as absorption heat pump, the steam of the lower pressure by doing merit in the steam turbine is as the driving heat source of absorption heat pump, the heat that the heat pump high temperature heat source obtains is used for heating in winter, connect the feed heating system heating boiler feedwater of steam turbine in summer; Concrete workflow is as follows: steam turbine (1) steam discharge enters condenser (2) and is condensed into water, is sent to boiler as boiler feedwater after the heat regenerative system of condensate pump (4) and low-pressure heater (6) composition; Liberated heat is by steam turbine bearing cooling system (3) cooling in rotating at a high speed for steam turbine (1), and the cool cycles water lines connects the low-temperature heat source of the evaporimeter (7-2) of steam absorption heat pump (7) as absorption heat pump (7); Doing the part of merit in the steam turbine (1) draws gas by the generator (7-1) of pipeline connection steam absorption heat pump (7), this steam is as the driving heat source of absorption heat pump (7), be cooled after the steam heat release, the hydrophobic of cooling formation is connected to the part of the low-pressure heater (6) of Steam Turbine Regenerative System as boiler feedwater by drain water piping; Condenser (7-4) is the high temperature heat source of steam absorption heat pump (7), and it emits heat to the external world, and the high-temperature water in the condenser (7-4) connects Water-supplying tee joint valve (9); In winter, by the switching of Water-supplying tee joint valve (9), the high-temperature water that steam absorption heat pump (7) produces is supplied with heat exchangers for district heating (10) and is further supplied with hot user and is used for heating; In summer, by the switching of Water-supplying tee joint valve (9), the high-temperature water that steam absorption heat pump (7) produces is by the feedwater of water water-to-water heat exchanger (5) heating Steam Turbine Regenerative System; Heat exchangers for district heating (10) all is connected backwater triple valve (8) with its backwater of water water-to-water heat exchanger (5), by the condenser (7-4) of triple valve connection steam absorption heat pump (7), forms water-flow circuit.Like this, the heat in the heat pump high temperature heat source is outwards supplied with hot user in winter, the condensate water raising boiler feed temperature in summer by heat exchanger heating Steam Turbine.This method has reduced the safe operation that power plant steam turbine group bearing temperature has been realized unit on the one hand, on the other hand its heat is outwards exported the cascade utilization that heat supply has realized energy by heat pump, having improved with Steam Turbine power plant is the heat-economy of the central heating system at center.

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